package com.ibm.demoBankJSF.utils;

import javax.faces.application.Application;
import javax.faces.application.FacesMessage;
import javax.faces.context.FacesContext;

import java.util.Locale;
import java.util.MissingResourceException;
import java.util.ResourceBundle;


public class MessageFactory extends Object {

    private MessageFactory() {
    }

    public static FacesMessage getMessage(String messageId) {
        Locale locale = null;
        FacesContext context = FacesContext.getCurrentInstance();
        // context.getViewRoot() may not have been initialized at this point.
        if (context != null && context.getViewRoot() != null) {
            locale = context.getViewRoot().getLocale();
            if (locale == null) {
                locale = Locale.getDefault();
            }
        } else {
            locale = Locale.getDefault();
        }

        return getMessage(locale, messageId);
    }


    public static FacesMessage getMessage(Locale locale, String messageId) {
        String
            summary = null,
            bundleName = null;
        ResourceBundle bundle = null;

        // see if we have a user-provided bundle
        if (null != (bundleName = getApplication().getMessageBundle())) {
            if (null !=
                (bundle =
                ResourceBundle.getBundle(bundleName, locale,
                                         getCurrentLoader(bundleName)))) {
                // see if we have a hit
                try {
                    summary = bundle.getString(messageId);
                } catch (MissingResourceException e) {
                }
            }
        }

        // we couldn't find a summary in the user-provided bundle
        if (null == summary) {
            // see if we have a summary in the app provided bundle
            bundle = ResourceBundle.getBundle(FacesMessage.FACES_MESSAGES,
                                              locale,
                                              getCurrentLoader(bundleName));
            if (null == bundle) {
                throw new NullPointerException();
            }
            // see if we have a hit
            try {
                summary = bundle.getString(messageId);
            } catch (MissingResourceException e) {
            }
        }

        // we couldn't find a summary anywhere!  Return null
        if (null == summary) {
            return null;
        }

        // At this point, we have a summary and a bundle.
        if (null == summary || null == bundle) {
            throw new NullPointerException();
        }

        return (new FacesMessage(summary));
    }


    //
    // Methods from MessageFactory
    // 
    public static FacesMessage getMessage(FacesContext context, String messageId) {
        return getMessage(context, messageId, null);
    }


    public static FacesMessage getMessage(FacesContext context, String messageId,
                                          Object params[]) {
        if (context == null || messageId == null) {
            throw new NullPointerException(
                "One or more parameters could be null");
        }
        Locale locale = null;
        // viewRoot may not have been initialized at this point.
        if (context != null && context.getViewRoot() != null) {
            locale = context.getViewRoot().getLocale();
        } else {
            locale = Locale.getDefault();
        }
        if (null == locale) {
            throw new NullPointerException();
        }
        FacesMessage message = getMessage(locale, messageId);
        if (message != null) {
            return message;
        }
        locale = Locale.getDefault();
        return (getMessage(locale, messageId));
    }


    public static FacesMessage getMessage(FacesContext context, String messageId,
                                          Object param0) {
        return getMessage(context, messageId, new Object[]{param0});
    }


    public static FacesMessage getMessage(FacesContext context, String messageId,
                                          Object param0, Object param1) {
        return getMessage(context, messageId, new Object[]{param0, param1});
    }


    public static FacesMessage getMessage(FacesContext context, String messageId,
                                          Object param0, Object param1,
                                          Object param2) {
        return getMessage(context, messageId,
                          new Object[]{param0, param1, param2});
    }


    public static FacesMessage getMessage(FacesContext context, String messageId,
                                          Object param0, Object param1,
                                          Object param2, Object param3) {
        return getMessage(context, messageId,
                          new Object[]{param0, param1, param2, param3});
    }


    protected static Application getApplication() {
        return (FacesContext.getCurrentInstance().getApplication());
    }


    protected static ClassLoader getCurrentLoader(Object fallbackClass) {
        ClassLoader loader =
            Thread.currentThread().getContextClassLoader();
        if (loader == null) {
            loader = fallbackClass.getClass().getClassLoader();
        }
        return loader;
    }


} // end of class MessageFactory
